Non-Pneumatic Tire Assembly with Compressed E-TPU Inlay
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pneumatic tires face issues with air leakage leading to flat tires, and non-pneumatic tires suffer from insufficient comfort and higher rolling resistance, as well as deformation during standstill, making them less suitable alternatives.
Innovation Solution
A vehicle wheel assembly featuring a non-pneumatic inner tire made of expanded polymer, such as expanded thermoplastic polyurethane (E-TPU), compressed to fit within a conventional outer tire and wheel rim, with an inlay between the rim bottom and inner tire to enhance support and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If non-pneumatic tires are used to eliminate flat tires, then reliability is improved, but riding comfort deteriorates
Solution Approach 1:
The patent employs a nested structure where an inner non-pneumatic tire is placed inside an outer pneumatic tire. The inner tire provides flat tire resistance while the outer tire provides comfort, and both work together as a integrated system. This resolves the contradiction by combining the advantages of both tire types without requiring abandonment of either.
Solution Approach 2:
The patent uses composite material structure by combining expanded polymer material for the inner tire with traditional rubber material for the outer tire. This composite approach allows the system to simultaneously achieve the reliability benefits of non-pneumatic tires and the comfort benefits of pneumatic tires.
2Reliability
If non-pneumatic tires are used to eliminate air leakage, then reliability is improved, but rolling resistance increases
Solution Approach 1:
The nested dual-tire structure allows the inner non-pneumatic tire to provide puncture resistance while the outer pneumatic tire maintains lower rolling resistance characteristics. The interaction between the two tires optimizes the overall rolling resistance performance.
Solution Approach 2:
The patent modifies the physical parameters of the inner tire by compressing the expanded polymer material to specific density ranges (150-750 kg/m³), which optimizes the balance between flat tire resistance and rolling resistance characteristics.
3Reliability
If non-pneumatic tires are used to eliminate air leakage, then reliability is improved, but deformation during standstill increases
Solution Approach 1:
The nested structure with the outer pneumatic tire provides structural support that prevents the inner non-pneumatic tire from deforming during standstill. The outer tire acts as a constraint that maintains the circular shape of the inner tire, eliminating the deformation issue while preserving the flat tire resistance benefit.
4Adaptability or versatility
If inner tire is compressed to fit in outer tire, then adaptability is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent specifies precise parameter ranges for the compressed state of the inner tire, including density (150-750 kg/m³) and cross-sectional area reduction. These controlled parameter changes enable adaptability to conventional wheel assemblies while providing guidance for manufacturing precision.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The assembly provides improved riding properties comparable to pneumatic tires, reduced rolling resistance, and increased tire life, while eliminating the risk of flat tires, offering a viable alternative with enhanced comfort and performance.
Implementation Method 1
The inner tire is made of an expanded polymer, such as an expanded plastic and/or an expanded rubber... which has been expanded by a blowing agent to thereby generate a closed cell structure in the material
Implementation Method 2
the inner tire in the assembly is in a compressed state S1, which state is compressed as compared to a relaxed state S2 when the inner tire is not enclosed by the outer tire
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
The invention relates to a vehicle wheel assembly, comprising 1) a wheel rim having two opposed circular rim flanges; 2) an outer tire having two beads secured at the circular rim flanges; 3) an inlay; 4) a non-pneumatic inner tire comprising expanded thermoplastic polyurethane (E-TPU), which inner tire is enclosed by the outer tire, the inlay and the wheel rim. The inner tire in the assembly is in a compressed state S1, which state is compressed as compared to a relaxed state S2 when the inner tire is not enclosed by the outer tire, the compression being such that the cross-sectional surface area SA of the inner tire, which area is perpendicular to the plane of the tire, is smaller in state S than in state S2.